General Parasitology
Zoology 4104
Matthew Bolek, LSW 415 bolek@okstate.edu
Introduction to Parasitology
• Each animal is a host of many parasites; thus,
there are far more parasitic organisms on earth
than there are nonparasitic organisms.
Introduction to Parasitology
• Each animal is a host of many parasites; thus, there are
far more parasitic organisms on earth than there are
nonparasitic organisms.
• It has been estimated that more than 50% of all
living plants and animals are parasitic at some
stage during their life cycle.
Introduction to Parasitology
• In this course we will concentrate on 3 major
groups of parasites:
1. Protozoa- flagellates, amebas, malarial
organisms
2. Helminths - parasitic worms such as the flukes,
tapeworms, and roundworms
3. Arthropods - insects and arachnids that are
ectoparasites and carriers (vectors) of diseases
Protozoa!
Helminths!
Arthropods!
Why do we study parasites?
• Parasites provide unique examples of
biological phenomena not found in freeliving organisms.
Why do we study parasites?
• Parasites provide unique examples of
biological phenomena not found in freeliving organisms.
• Medical Importance
Why do we study parasites?
• Parasites provide unique examples of
biological phenomena not found in freeliving organisms.
• Medical Importance
• Veterinary Importance
Why do we study parasites?
• Parasites provide unique examples of
biological phenomena not found in freeliving organisms.
• Medical Importance
• Veterinary Importance
• Economic Importance
Medical Importance of Parasites
• Humans are hosts to many species of
parasites.
Medical Importance of Parasites
• Humans are hosts to many species of parasites.
• Many of these parasites are causative agents
of major public health problems of the
world.
Recent estimates of the number of people
infected with parasites in the world are:
Ascaris
Hookworms
Whipworms
Filarial worms
Malaria
Schistosomes
Amebiasis
Taeniad tapeworms
Clonorchis
Chagas’ Disease
1.3 billion
1.3 billion
1 billion
657 million
500 million
270 million
50 million
50 million
20 million
15 million
These parasites cause untold suffering and death
in the world today.
Examples of Medical Importance
in the World
Examples of Medical Importance
in the World
• The life expectancy of an Egyptian is in the
mid-40's due to Schistosomes.
Examples of Medical Importance
in the World
• The life expectancy of an Egyptian is in the mid-40's
due to Schistosomes.
• 15 million children in the world will die this
year from a combination of malnutrition and
parasites.
Examples of Medical Importance
in the World
• The life expectancy of an Egyptian is in the mid-40's
due to Schistosomes.
• 15 million children in the world will die this year from
a combination of malnutrition and parasites.
• Over 1 million African children will die this
year from the effects of malaria.
Examples of Medical Importance
in the World
• The life expectancy of an Egyptian is in the mid-40's
due to Schistosomes.
• 15 million children in the world will die this year from
a combination of malnutrition and parasites.
• Over 1 million African children will die this year from
the effects of malaria.
• Many cases of plague, transmitted by
fleas, still occur throughout the world.
Examples of Medical Importance
in the U.S.
• We in the comfort of the U.S. are not
immune from parasites.
Common parasitic diseases in the
U.S. include:
Pinworms
Giardiasis
Dog roundworms
Ticks
Importation of Parasites from
Tropics to the U.S.
• Movement of persons from all areas of
the world have introduced parasitic
diseases into the U.S.
Importation of Parasites from
Tropics to the U.S.
• Movement of persons from all areas of
the world have introduced parasitic
diseases into the U.S.
– Numerous cases of malaria are brought back
by vacationers from the tropics.
Importation of Parasites from
Tropics to the U.S.
• Movement of persons from all areas of
the world have introduced parasitic
diseases into the U.S.
– Numerous cases of malaria are brought back by
vacationers from the tropics.
– Service personnel are often employed in
areas endemic with many parasites.
Importation of Parasites from
Tropics to the U.S.
• Movement of persons from all areas of
the world have introduced parasitic
diseases into the U.S.
– Numerous cases of malaria are brought back by
vacationers from the tropics.
– Service personnel are often employed in areas
endemic with many parasites.
– Many immigrants have brought their
parasites with them.
Veterinary Importance of
Parasites
Veterinary Importance of
Parasites
• In Africa, cattle cannot be raised in an area
equal to that of the U.S. due to trypanosoms.
Veterinary Importance of
Parasites
• In Africa, cattle cannot be raised in an area equal to
that of the U.S. due to trypanosoms.
• A poultry farmer can be wiped out by coccidia.
Veterinary Importance of
Parasites
• In Africa, cattle cannot be raised in an area equal to
that of the U.S. due to trypanosoms.
• A poultry farmer can be wiped out by coccidia.
• Cattle, pigs, and sheep infected with parasites
fail to gain weight and may not reproduce.
Veterinary Importance of
Parasites
• In Africa, cattle cannot be raised in an area equal to
that of the U.S. due to trypanosoms.
• A poultry farmer can be wiped out by coccidia.
• Cattle, pigs, and sheep infected with parasites fail to
gain weight and may not reproduce.
• Dogs may become infected with heartworm and
die if untreated.
Veterinary Importance of
Parasites
• In Africa, cattle cannot be raised in an area equal to that of the
U.S. due to trypanosoms.
• A poultry farmer can be wiped out by coccidia.
• Cattle, pigs, and sheep infected with parasites fail to gain weight
and may not reproduce.
• Dogs may become infected with heartworm and die if
untreated.
• Cats are infected by many species of
protozoans and helminths.